Contour-base for projectiles.



C. DAVIS.

CONTOUR BASE FOR PROJECTILES. APPLICATION FILED SEPT. 30. 1913.

1, 14 1,042. Patented May 25, 1915.

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CLEIAND DAVIS, OF THE UNITED STATES NAVY, ASSIGNOR TO ORDINANCE DEVELOP-MENT COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DEL-AWARE.

CONTOUR-BASE FOR PROJECTILES.

Specification of Letters Patent.

, Patented May 25,1915.

Application filed September 30, 1913. Serial No. 792,680.

To all whom it may concern:

Be it known that I, CLELAND DAvrs, commander, United States Navy, acitizen of the United States, residing-at Washington, in the District ofColumbia, have invented certain new and useful Improvements inContour-Bases for Projectiles; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

The object of my present invention is to provide means for decreasingthe resistance of the air to the flight of a projectile moving at highvelocity. The universal form of projectile consists of a cylindricalbody with a tapering ogival, or head, and a flat base; by changing thecontour or form of the point of the projectile, its flight through theair has been greatly facilitated, but no practical means have yet beendevised to apply the contour to the base of the projectile to reduce thebackward pull during its flight through the air. As is well known, thisbackward pull amounts to a considerable portion of the loss of energy,or velocity, for a given distance. T his is due to the vacuum, orpartial vacuum, which is created by the displacement of the molecules ofair by the passages of the shell itself, which, on account of thevelocity of the shell, have not time to close in on the base andequalize the pressure. In other words, the object is to provide such aform for the base of the projectile as will give a minimum resistance toreduce its retardation in air, in a manner similar to providinggradually tapering lines and curves for the hull of the ship, tominimize the resistance of its passage through the water.

With a projectile, the problem is somewhat complicated, owing to otherqualities which it is necessary for the projectile to possess, as, forexample, the quality of perforating armor plate, and also the ability tocarry a large bursting charge. The shape of the projectile is alsoimportant when the capacity of the powder chamber is considered, and afiat base projectile, such as is now universally used, enables a maximumcharge to be used in the powder chamber, with due regard to the weightand shape.

In order to overcome the objections of increasedweight, reduction ofcapacity of bursting charge and reduction of the size of powder charge,and at the same time give the proper form of base, I provide a hollowattachment tapering with a curve to give a minimum resistance Thisattachment may be screwed on in the case of fixed ammunition, or slippedon and locked in place in the case of larger calibers, in the mannershown, or in any other convenient way.

The attachment is filled with powder and this forms part of thepropelling charge itself, and is provided with an aperture on the rearend, which permits of the equalization of the pressure of the gasesinside and outside the hollow contour. As the projectile travels downthe bore, powder contained in the hollow contour evolves its gases, andthus plays its part in giving the projectile its normal velocity at themuzzle.

I do not limit myself to the exact form or shape of contour base, asthis can only be determined by long experiment. But even a slightelongation of the base will have an appreciable effect in reducing thenegative acceleration of the projectile. For larger caliber guns, thecontour may be included in the first section of the powder charge, sothat the projectile may be first loaded into the gun in the usual way.The first section of the powder charge containing the contour is thenloaded and shoved up against the base of the projectile, slipping overthe latter and being locked in place.

Reference is bad to the accompanying drawings in which the same partsare indicated by similar reference symbols throughout the several views.

Figure l'shows a fixed ammunition con structed according to myinvention;' Fig. 2 shows a section through part of the bore and powderchamber of the gun, with the projectile and first section of the powdercharge in elevation, and showing the invention as applied for use withguns of heavy caliber; and Fig. 3 is a detail showing in section a partof the projectile and the first section of the prrp lliug charg degachedtherefrom, and including the contour ase.

Referring first to Fig. 1, 1 represents the projectile, 2 the contourbase screwed on the projectile, and 3 the cartridge case constructed ofthe usual or any desired form, and containing the propelling charge l,part of which propelling charge is also contained in the interior of thecontour base 2, as shown.

In theform of device shown in Figs. 2 and 3, 5 represents part of thegun body having the bore 6 and powder chamber 7 of 1 the usual ordesired form. 8 represents the projectile, which is cut away at its'rearend, as at 0. To fit into the large end of the contour base, the reducedportion of the shell is provided with sockets 9 to hold the taperedblocks 10 and the springs 11, which tapered blocks slip under the wedgefaces 13 in the large end of the contour base, and spring out under theaction of the springs 11 into the sockets 14 in the contour base 12.While the springs 11 normally tend tohold the locking blocks 10 inengagement, the revolution of the shell will create such centrifugalforce as will tendto hold the same in the outer or looking positionafter the parts are assembled. The contour base 12 is preferablyprovided with a suitable disk 15, of celluloid, or other combustiblematerial, tending to keep its larger end always open and ready toassemble with the shell; and the body of the contour base is filled withpowder 18, and is mounted in any suitable container 16, preferably theusual silk, or flannel bag bound around with tapes 17, but any suitablecontainer may be used. Thus, the contour base and the container with thepowder included in both forms While I have shown spring-operated lookingblocks connecting the shell and the contour base together, any othersuitable means connecting these two members may be adopt ed, desired;and I do not mean to limit iny invention to any particular means foraccomplishing this purpose.

It will be obvious that various changes might be made in the hereindescribed apparatus, and in the constructions, combina-' tions andarrangements of parts without departing from the spirit of my invention.

vHaving thus described my invention,.what

I claim and desire to secure by Letters Patent of the United Statesis 1. The combination with a projectile of standard design and thepropellingicharge thereof of a hollow metal contour base secured to therear end thereof and forming with the outer shell of the projectile acontinuous substantially ogival curve, the hollowcontour base having alength of onehalf or more of the length of the projectile to which it issecured, and being provided with an enlarged opening in its rear, saidcontour base projecting into the propelling charge and containing aportion thereof, substantially as described.

2. The combination with a projectile of standard designand thepropelling charge thereof of a hollow metal contour base secured to therear end thereof and forming with the outer shell of the projectile acontinuous substantially ogival curve, the hollow contour base having alength of one-half or more of the length of the projectile to which itis secured, and being provided with an enlarged opening in its rear,said contour base projecting into the propelling charge and containing aportion thereof, with means for detachably connecting said contour baseto the rear of the projectile, substantially as described.

3. The combination with a projectile of standard design and thepropelling charge thereof of a holder for a section of the propellingcharge, a hollow metal contour base mounted in said holder and adaptedto slip over the rear end of the projectile, the said contour base whensecured to the rear end of the projectile forming with the outer shellof the projectile a continuous substantially ogival curve, the saidhollc w contour base being provided with an enlarged opening in its rearend, and the propelling charge being mounted. in said holder and partlyin, said hollow contour base, with means for detachably connecting saidcontour base and with it said holder to the base of the projectile,substantially as described.

, 4. The combination with a projectile of standard design of a holderfor a section of the propelling charge, a hollow metal contour basemountedin said holder and adapted to slip over the rear end of theprojectile, the said contour base when secured to the rear end of theprojectile forming with the outer shell of the projectile a continuoussubstantially ogival curve, the said hollow contour base being providedwith an enlarged opening in its rear end, and'the propelling chargebeing mounted in said holder and partly in said hollow contour base,with means for detachably connecting said contour base and with it saidholder to the base of the projectile, said means comprisingspring-impressed tapered blocks engaging in v sockets in the contourbase, substantially as described. I

In testimony whereof, I affix my signature, in presence of twowitnesses.

CLELAND Davis.-

S. WV. SQHARFF.

